Magnesium base alloy



Patented July 26, 1938 i UNITED STATES PATENT OFFICE MAGNESIUM BASEALLOY William 0. Binder, Niagara Falls, N. Y., aasig'nor to The DowChemical Company, Midland, Mich, a corporation oi Michigan 'No Drawing.Application April :4, 1937, Serial Claimsa (Cl. 75+168) This inventionrelates to magnesium alloys and Properties of heat treated alloys moreparticularly to those containing minor percentages of lead, manganese,and zinc. Tensile Ymd One of the important problems confronting thComposition strengt strength. 51 2 5 magnesium industry is theproduction oi. mag- 5 nesium alloys that possessgood strength and re- M+1 W 7 9 lated properties, good corrosion resistance, and v ,600 M &2good casting and fabricating characteriaslililcs. milifiiMfliigiiigfifii131% ir s The commercial uses for which magnesium l oys M L5 M Pb 19 mo10 are suited depend in many instances on theavailufiilsgjnflifiipbxrgzri 221100 10 ability of an alloy possessingtwo or more of the above mentioned characteristics. The t lea] to rt 1mrovement The object of this invention is to prepare mag- 1 treated 3 g 3i as 5;; the nesium alloys that combine to a marked degree good physicalproperties, high corrosion resist- P t s of heat treated and aged alloys15 ance, and ease of casting and fabricating. Other objects andadvantages will appear as the de- Tens, Yield B u scription proceeds. a{g 2 f f g militia My invention is based on the discovery that .ls n. Yhighly desirable and useful alloys can be made 20 from magnesium byalloying therewith approxifiiiifigfifliigggfirgaag 1183 mately 0.5 to 22per cent of lead, approximately M 0.1 to 1.5 per cent of manganese, andapproxigiiggfifliigggtrzgiri g' mately 0 .5 to 10 per cent of zinc, andthat such a 25 alloys constitute new product possessing highly Anotheroutstanding advantage of these new 25 desirable combinations ofproperties.

I have discovered that by adding zinc in amounts of about 0.5 to 10 percent to the magnesium-manganese-lead alloys,- new alloys are producedwhose physical properties are distinctly superior to themagne'sium-manganese-lead alloys and that these new alloys are amenableto heat treatment, thereby resulting in still greater propertyimprovement. This can be illustrated, which make them vama'ble for manytypes of for example, by the addition of 2 per cent of zinc v I 35 t0the ternary masneslum-l- 1.5 pe cent of Corrosion resistance ofMa-Mn-Pb-Zn alloys ganese+4 per cent of lead alloy and to the terin 3%NaCl solutlou for 1 week (ma/cms/day) nary magnesium-{-15 per cent oimanganese+12 magnesium-manganese-lead-zinc alloys is that the abovedescribed property improvement has been obtained with little to no lossin corrosion heat treated and aged alloys. These alloys, therefore,possess excellent combinations 01' good physical properties and'highcorrosion resistance per cent of lead alloy. 7 mm 40' Y Composition Casttreated 40 Properties of cast alloys d d M 'rt Mn-H r v are a1 0.1 M mm... tat: sang; a: 2-: a: composition ag 1 mg. gr s ang: I Mg+l. mm r#332 III; III 013i 017 01s 4.5

' rel-Wags; a H a I l I! n l M +1.6'7M +4 Pb 400 4,200 no MEH'WZMgfl215mm 1%,. mm 3 Mg+l s Mn-i-l ,Pb-H o zn o w 1 o v 1 a v M 1. M gi g ggiggg gig g: The above alloys may be prepared'by conven- 5o tionalmethods oi making magnesium alloys as a'bymelting-magn'esiumwithaprotectivefluxand The property-'iseprovemente'dle; 1 addingtheretcthe. respective alloying ingredi-- ence oi zinc intne heat treated alloys he eats. either singly or simultaneously.Castings ,55 illustrated bytheiollowing data: irom my newmagnesium'alloys can be made in resistance, particularly in the heattreated and 30 heat.treatment consists of 16 to-lB' hours at 790-840 E,while aging may be conducted at approximately 350" F. for 16 to 18hours. It is often advantageous to give these alloys a preliminary heattreatment of 4 to 8 hours at approximately 650-700 F. prior to the abovedescribed heat treatment. Alloys for plastic deformation purposes shouldnormally contain 1 to 6 per cent of lead, 0.5 to 1.5 per cent oimanganese (preferably about 1.2 per cent), and oi 0.5 to 3 per cent ofzinc. Fabrication steps by plastic deformation operations are generallyperiormed at GOO-750 F. v

Other modes of applying the principle of my invention may be employedinstead of those explained, change being made as regards the ingradients and the steps herein disclosed, provided those stated by anyof the following claims or their equivalent be employed.

2 per cent of zinc, the

I particularly point out and distinctly my invention:

l. A magnesium-base alloy containing from about 0.5 to 22 per cent oflead, from about 0.1- to 1.5 per cent of manganese, and from about 0.5to 10 per cent of zinc, the balance being magnesium.

2. A magnesium-base alloy containing from about 4 to 12 per cent oflead, from about 0.8 to 1.5 per cent or maganese, and from about 3 to 6per cent of zinc, the balance being magnesium.

3. A magnesium-base alloy containing from claim as about 1 to 6 per centof lead, from about 0.5 t 1.5 per cent of manganese, and from about 0.5

to 3 per cent of aim, the balance being magnesium. a

4. A magnesium-base alloy containing about 12 per cent of lead, 1.5 percent of manganese, and 4 per cent of zinc, the balance being magnesium.

5. A magnesium-base alloy containing about 4 per cent of lead, 1.2 percent of manganese, and balance being magnesium.

WILLIAM 0. BINDER.

